You may be conflating two distinct problems. The Y's suspension (based on a few admittedly not very lengthy test drives on my part) did not seem well settled in terms of controlling body movement while concurrently absorbing irregularities in whatever surface you're driving over. My biggest complaint is on freeway sections with expansion joints, where it bobs fore and aft like a short wheel base vehicle (reminds me of my 1994 Jeep Wrangler actually), which was a bit surprising.Rigid hatch stops will solve all the ‘perceived’ harsh ride issues and boominess, which also causes ear and sinus discomfort for some.
$4 DIY that will transform your Model Y.
Bump stops are supposedly the cure for what sounds like (didn't experience it) pressure changes inside the vehicle, perhaps associated with going over surfaces like the expansion joints I mentioned. They are not going to do anything about the fore/aft bobble head problem that I experienced, unless there is something that I didn't grok after reading a few threads associated with the boominess / bump stop hack.